The goal of the proposed project is to understand the relationship between social stress and progression of immunodeficiency disease. In humans, the quality and stability of social life have been implicated as important factors in the progression of diseases such as cancer and cardiovascular disease. HIV disease is often associated with social disruption, (e.g., stigma, bereavement), and social stress has been suggested as contributing to the progression of HIV infection. The proposed research involves study of the role of social conditions (defined as stable and unstable social groups) in immunodeficiency disease progression, using the SIV-macaque model of HIV infection. The research plan specifically aims to continue an ongoing study of social stability and instability, and the consequences of these social conditions for behavioral, neuroendocrine, immunological, and disease processes in SIV-inoculated and control monkeys. The research is expected to provide important new information on the relationships between social stress and support, and their behavioral, neuroendocrine, and immunological sequelae in the course of immunodeficiency disease.